Safety device



July'21, 1925'.

W. C. BAXTER SAFETY DEVICE Filed Feb. 20, 1922 Patented July .21, 1925,

UNITED STATES PATENT OFFICE.

WILLIAM C. BAXTEB, OF BEVERLY, MASSACHUSETTS, ASSIGNOB TO UNITED SHOE MACHINERY CORIORIATION, O IPATERSON, NEN JERSEY, A CQBPQB ATION OF NEW JERSEY.

" SAFETY DEVICE.

To all whom it may concem Be it known that I, WILLIAM G. BAXTER, a citizen of the United States, residing at Beverly, in the county of Essex and State of Massachusetts, have invented certain Improvements in Safety Devices, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figures.

This invention relates to safety devices and more particularly to that class of safety devices in which a shield or guard is provided to protect the operator from injury by moving parts of a machine or by other parts capable of causing injury if left unguarded.

It is an object of the invention to provide improved means for preventing operation of a machine when such a guard or shield is out of operative or covering position with respect to machine parts which may, when unprotected, cause in ury to the operator.

In the illustrative construction, and in accordance with a feature of the invention, a switch in an electric circuit is provided for controlling the power means of the machine, provision being made for locking the switch against movement to start the machine in operation when the guard or shield for a dangerous part of the machine is in inoperalive or uncovering position, the construction being preferably such that as soon as the guard or shield is returned to operative or covering position the switch is disconnected from the locking means and may be operated in the usual manner to start the machine in operation.

In another aspect, the invention resides in the combination with a guard or shield which normally covers a movable machine part capable of causing injury to the operator, of means, connected with or forming a art of the switch, for preventing movement of the shield to inoperative or uncovering position. Conveniently, the manually operable member of the starting means of the machine is itself the means for preventing movement of the shield to inoperative position while the machine is running.

Other novel combinations of parts and details of construction, will be described in the specification and pointed out in the appended claims.

In the drawings Figure 1 is a view in side elevation of a machine showing one embodiment of the invention;

Fig. 2 is a detail view showing certain of the parts in different relative positions with respect to the disclosure in Fig. 1; and

Fig. 3 is a detail view in perspective with the parts substantially in the position shown in Fig. 1.

For the purposes of illustration the invention is disclosed inconnection with a heel lift cutting machine of the type shown in Patent No. 1,344,975, granted June 29, 1920 upon application of William C. Baxter. In this machine there is shown a pitman 4: operated from a crank or eccentric 6 on the forward end of the main shaft which carries the fly wheel 8 and belt pulley 10. Operated by the pitman 4 is a block carrier 12 adapted to carry a block (not shown) for co-operation with a die (not shown) in cutting blanks from sheet material. For the belt which runs on the power pulley 10 there is provided a stationary shield 11. For a complete disclosure of the blank cutting machine reference may be had to the patent referred to above.

For covering the fly wheel 8 there is pro vided a shield 14 which may entirely surround the fly wheel or only that part of the latter which is readily accessible to the operator. For mounting the shield or guard 1e there is provided a bar 16 to which this shield is rigidly connected so as to be moved with the bar, the connection comprising, in the illustrative construction, a sleeve 18 adjustably bolted to the bar 16 and having a projecting portion 20 upon which the shield 14 is secured by bolts, as shown at 22. EX- tending from a bracket 24: attached to the machine frame is a sleeve member 26 which slidaloly receives the bar 16, the latter being movable in the sleeve to carry the attached shield or guard from and into covering position with respect to the fly wheel 8. For moving the bar 16 there is conveniently provided a handle 28 at that end of the bar which is adjacent to the front of the maehine. the said handle being preferably detachable so as to render the assembling of the device a relatively easy operation. In the sleeve 26 is a spring-pressed pin 30 adapted to set its lower end in relatively shallow, cup-shaped depressions, (not shown) in the upper surface of the bar 16 so as to hold the bar 16 yieldingly in either of its two positions, that is, in the position showniniFig. 1 wherein the shield has been moved to uncovering position with respect to the fly wheel 8, and in the position shown in Figure 2 where the shield is in covering relation to the fly wheel 8. As a matter of convenience the sleeve 18 i's of such a length and so adjusted that it serves as a stop in connection with the sleeve 26 for positioning the shield in its uncovering" position with'res'pect to'the fly wheel 8.

Power means, not shown, is provided for furnishing power for driving the main shaft, the said means comprising. conveniently an electric motor (not shown) controlled from a switch 34- for opening. and closing the motor circuit. If desired the power means for driving the machine may be the ordinary line shaft and belting to a power pulley on the machine, a clutch being interposed between the power pulley and themain shaft of the machine, which clutch may be controlled by electric' means comprising an ordinary form of commercial switchlikethat shown 3 1 in the figures of the drawing.

It will be understoodlthat the switch 34tis merely a-n illustrative starting means for controlling the operations of the machine through the starting. and stopping of the power means directly concerned in operating the machine. As above stated the switch 34; is awell known commercial form of switch in that it consists of a stationary sleeve member 40'which may'befixedly secured to a bracket 42 or to any other part of the frame of the machine. Conveniently the sleeve member 40 carries portions 44 which are stamped or otherwise provided with the usual directing legends Off and Onf Inside of the sleeve is located the rotary switch member 46' which is dome-shaped and carries the handle or finger piece 48. Aswill be understood the current is turned off and on by manipulation of the member 46 in the ordinary manner. \Vhile the switch 3 1' as a whole has been described as an ordinary commercial switch, it differs in one important particular from those on the marketin that the rotatable part 46 of the switch is provided with a recess or a passageway 01' with openings 50 for the reception of a pin 52shown as mounted adj'ustably' in the end or an arm 54 extending from the sleeve 18 on the bar 16' As stated above, the sleeve 18 carries or has firmly attached thereto the shield or guard 14; for the fly wheel 8. Itfollows' that when the guardisshifted to the left in; Fig.1 to uncover the fly wheel 8, the pin" 52 is' also moved to the left. Since the switch 34 is closely adjacent to the end of the pin. 52 and in the path of movement of the pin, the switch serves under certain con ditions as a stop for preventing movement of the guard and pin as: disclosed in Figure 2' of the drawings. If the switch member 16 be turned so that the finger piece 48 is pointing to the word0flf,- "their one of the op'e'n ing's 50 in the member 16 is positioned in line with the pin 52. Under these conditions, the-pin 52 and hence also the guard 14; may be moved to the left in Fig. 1 to withdraw the guard from the fly wheel 8, the pin 52 entering one of the openings 50 in switch member-"46', whereby the switch member 46 is locked against turning movement, as indicated in Figs. 1 and 3' of the drawings. Before the switch can be manipulated to close the circuit and thus to start the ma'cl'iin'e in operation, the pin 52'must be removed and this necessitates return of the guard 14' into coveringirelation with re spect to the flywheel 8. lVIoreovenasst'ated above, the guard cannot be moved to uncover the fly wheel 8 until the switch is manipulated to stop the machine. The purpose here is to prevent uncovering of a dangerous part of a machine while it is in motion, that is, while the machine" is in operation.

The invention is to be considered broadly as a safety device" since it requires that a movable part of the machine, capable of causing injury to the operator, shall covered-by the guard or shield before'the cur rent can be turned on to start the" machine in operation. For example, in the illustrative machine, it is sometimes necessary to turn the main shaft over by hand in order to test the adjustment ofthe'die and block with respect to each other when a. new die or one of a different size is introduced into the machine In providing machines with individual electri'c 'motor' drive it is desirable from the standpoint of economy and efficiency to'select a motor wliic-lrwillhave a moderate amount more power than enough to' drive the machine" under normal conditions. Hence, if the motor he overloaded through inadvertence or carelessness on the part of the operator it may readily become stalled, in which case, it may be necessary to turn the main shaft overb'y' hand to free the machine from. the worln. Hence for any of these reasons, the g'uard 14 may be shifted to the position shown in Fig'. 1', in order to permit-the operator toinsert a bar or rod'58 (Fig. 3)'into one of the openings in the fly wheels for the purpose of turning the shaft over by hand. ith the guard in the position shown in Fig. 1', the machine cannot be'started in operation since the pin 52'has entered the passageway inthe switch member 46 and locked tli'e latter against Inanipulation. It willfbe' obvious that so long as the bar 58, remains in one of the openings 60, the guard 14 cannot be returnedto covering position with" respect to the fly wheel 8 and until this is accomplished, the starting til means is locked against such manipulation as would result in starting the machine in operation. In other words, until the shield or guard 14: is returned to its operative or covering position with respect to the fly wheel 8, the pin 52 which moves with the guard remains in locking relation with respect to the switch member 16. In returning the guard to operative position the pin 52 is removed from the switch member 46, thus unlocking the latter so that it may be manipulated to start the machine in opera tion.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States is 1. In a machine of the class described, a member capable when uncovered of causing injury to the operator, a shield for said member, power means for operating the machine, electric starting means for the power means comprising a movable switch member, and a latch controlled by the shield so that when the latter is moved to uncovering position with respect to the first mentioned member the latch will move into engagement with the switch member to lock the latter against movement, said movable switch member in one of its positions being operative to prevent uncovering movement of the shield with respect to the first-mentioned member.

2. In a machine of the character described, a member capable when uncovered of cansing injury to an operator, a shield for covering the member, power means for operating the machine, a. switch for starting and stopping the power means, said switch having a recess therein, and a pin carried by the shield and adapted to enter the recess of the switch to lock the latter against movement when the shield is moved to uncovering position with respect to said member.

3. In a machine of the character described, a member capable when uncovered of causing injury to an operator, a shield for the member, power means for operating the machine, a starting member for causing initiation of operations by the power means, and a pin carried by the shield and operative to hold the shield against movement toward uncovering position with respect to the first mentioned member while the machine is in operation, said starting member having a recess to receive the pin when the starting member is in position which it occupies before being moved to cause initiation of the power operation of the machine.

4:. In a machine of the character described, a member capable when uncovered of causing injury to an operator, a shield for the member, power means for operating the machine, a switch member for initiating operation of the power means, and a pin carried by the shield and operative to prevent uncovering movement of the shield when the switch is in position to initiate and maintain operation of the power means, said switch member having a recess for receiving the pin when the switch member is in position to open the circuit that controls the power means, thus permitting the shield to be moved to uncovering position with respect to the first mentioned member when the machine is at rest.

5. In a machine of the class described, a fly wheel having openings therein adapted to receive the bar by which the fly wheel may be turned by hand, a shield for covering the fly wheel, power means for operating the machine, a rotatable switch for controlling the power means, said rotatable switch having a recess therein, and a pin carried by the shield and movable into the recess in the switch to prevent rotation of the latter when the shield is moved to uncovering position with respect tothe fly wheel.

6. In a machine of the character described, a movable member capable when uncovered of causing injury to an operator, a shield for the member, power means for operating the machine, a switch member for initiating operation of the power means, and a pin carried by the shield and operative in conjunction with the switch member to prevent uncovering movement of the shield when the switch is in posit-ion to initiate and maintain operation of the power means, said switch member having a recess for receiving the pin when theswitch member is in position to open the circuit that controls the power means, thus permitting the shield to be moved to uncovering position with re spect to the first mentioned member when the machine is at rest.

In testimony whereof I have signed my name to this specification.

WILLIAM G. BAXTEn, 

